Polyolefins including polybutylene and polypropylene are very well known in the art. It is known that polybutylene is non-polar, and exhibits little or no adhesion to substrates such as metals, and to polar polymers such as nylon, and PET. Attempts to improve on the adhesion of polybutylene to polar substrates by utilizing application methods inclusive of powder coating, lamination, co-extrusion, have been unsuccessful.
For some applications of polybutylene wherein the polybutylene is used to provide a protective coating for polar surfaces, e.g. metal surfaces, good adhesion of polybutylene to the polar surface is required. A conventional method of improving the adhesion of polybutylene to such polar surfaces by using an adhesive tie-layer or a liquid primer in between the polybutylene and the polar surface. Such tie-layers or primers include maleated KRATON.RTM., ethylene acid copolymer such as ethylene acrylic acid or ethylene methacrylic acid copolymers, epoxy resins, and polyurethane. Conventional methods for inserting the tie-layer or applying the primer known in the art, can be utilized. The drawbacks of these tie-layer and primer methods include the requirement of additional materials, and an increase in costs.
Because of the present and increasing need of polybutylene in adhesive applications, it remains desirable to discover methods and/or materials which have the capability of improving upon the adhesive quality of polybutylene. The present invention represents one such discovery.